Supporters include Brian Eno and Arundhati Roy. Critics say sanctions will be counter-productive.

The celebrated novelist, critic and artist John Berger today calls on British writers and artists to undertake a "cultural boycott" of Israel. In a letter to the Guardian, co-signed by, among others, the artist Cornelia Parker, the musician Brian Eno, and writers Arundhati Roy and Ahdaf Soueif, Berger calls for support for "our Palestinian and Israeli colleagues". He suggests boycott tactics; in his case it meant declining to be published by a large mainstream Israeli publisher, he says.

Yesterday he said of the boycott: "It could be a factor in Israeli policy changing. Of course its effects will not be gigantic but it is a way of not staying silent. It is a very personal call... a way of encouraging the very courageous Israelis who oppose their government and an encouragement to Palestinians to somehow go on surviving." He made a clear distinction between individuals and state-sponsored events or institutions. "It is not a question of boycotting Israeli artists," he said.

The film-maker Ken Loach, who backs the boycott, said he would not take part in state-sponsored Israeli film festivals.

However, Nicholas Hytner, director of the National Theatre, said: "There are countless Israelis who vehemently oppose their government... many are artists and academics, and none of them are prevented from expressing their opposition... It seems profoundly counter-productive to cease contact with precisely that section of Israeli society most likely to provoke a change in direction within Israel."

Richard Eyre, the theatre director, said: "I would have said during apartheid in South Africa sanctions... were effective, but so many people since then have said they were counterproductive. It's not cut and dried. Anything that boycotts Israel means we are in danger of cutting off access to [those] we should be speaking to."

The playwright Mark Ravenhill said it was good to keep a dialogue open with those challenging the government. "A cultural boycott runs the risk of stopping that dialogue and support." Michael Berkeley, the composer, said: "Sometimes it is only through the arts that a link remains open."